Keywords: sociolinguistics, song, slang words. slang is an informal language that is described as an ordinary or casual conversational language used in interaction among people who know each other and feel relatively unconstrained. the sources of the data are lyrics of 10 songs taken from saykoji’s album. the research design used in this study is qualitative research with document analysis as the technique of data collection. the findings show that are 66 slang words found in saykoji’s album. those 66 slang words are then categorized into types of meanings of slang words as proposed by leech (1983), namely: conceptual meaning (34), affective meaning (16), stylistic meaning (4), collocative meaning (12), connotative meaning (0), reflected meaning (0), thematic meaning (0). the conceptual meaning was found to be the most used in the saykoji’s album. the result could be associated with the fact that songs from saykoji’s album mostly use words appearing in the current era without